Percentage Calculator
Three common percentage calculations in one place — pick the one you need.
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What is X% of Y?
15% of 80 is 12
X is what percent of Y?
20 is 25% of 80
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Percentage increase / decrease
That's an increase of 30%
Frequently asked questions
How is percentage change calculated?
Percentage change = ((New value − Old value) ÷ Old value) × 100. A positive result is an increase, a negative result is a decrease.
Can I use negative or decimal numbers?
Yes, all three calculators accept negative numbers and decimals.
Is anything I type here saved or tracked?
No — every calculation happens instantly in your browser. Nothing is uploaded, logged, or stored.